Anaerobic digestion has been used in local communities to generate natural gas and other valuable bio-chemical streams. Anaerobic digestion is a series of processes in which microorganisms break down biodegradable material in the absence of oxygen. It has widely been used to treat wastewater sludges and organic wastes, such as sewage sludge and manure. Anaerobic digestion provides a renewable energy source because the process produces a methane and carbon dioxide rich biogas suitable for energy production.
Local anaerobic digestion systems have offered the cheap, low-cost energy for cooking performing daily tasks and have been recognized by the United Nations Development Program as a decentralized source of energy. Pressure from environmentally-related legislation on solid waste disposal methods in developed countries, such as the United States, has increased the application of anaerobic digestion as a process for reducing waste volumes and generating useful by-products. Anaerobic digestion has typically been used to process separated fractions of municipal wastes.
New technologies are emerging to convert cellulose-containing biomass into useful products, such as electricity, energy, and fuel. Much research has focused on the utilization of algae because of its ability to grow quickly and in many different conditions. In addition, algae can comprise high amounts of lipids and hydrocarbons as compared to other biomass. There is a need in the art to convert biomass, including aquatic biomass, into useful products without requiring high costs or energy demands.